The invention relates in particular to a mobile telephone having attenuation control, as used in connection with handsfree systems. Telephone terminal devices should maintain a certain decoupling between received and transmitted signal in order to operate properly or to comply with regulatory requirements. In the case of handsfree terminal devices the high levels of amplification required would make it necessary to introduce a very great attenuation/decoupling in order to avoid, for example, feedback, echoes or what is termed reverberation.
This attenuation/decoupling should be implemented for example either by a deviation control unit and/or by way of an acoustic echo canceller and/or by a combination of different decoupling methods. A deviation control unit inserts the necessary attenuation for example alternately in the transmitting or in the receiving direction.
Particularly in the case of mobile handsfree devices, such as e.g. cordless telephones or mobile telephones, the decoupling possible by an acoustic echo compensator is not usually sufficient on its own, however, to get by without an additional deviation control unit and/or further decoupling measures. A problem in this case is that said deviation control unit must be adjusted to the most unfavorable position, e.g. lying on the microphone, in order that the mobile handsfree device will still also operate sufficiently well under these “bad” conditions.